Chelsea manager Graham Potter must juggle his new signings for their Champions League clash with Borussia Dortmund on Wednesday.
Under Uefa rules, the club were only able to register three of the eight players brought in during the January transfer window in their 25-man Champions League squad for the knockout stages.
The west London club splurged more than £300 million ($362m) on new players in the winter window to bring their total spending since American Todd Boehly took over the club from Roman Abramovic in May last year to more than £600m.
The selection headache means that Potter is likely to call on £107m British record signing Enzo Fernandez, loan signing Joao Felix and £88.5m Mykhailo Mudryk for the last-16 first-leg match against Dortmund in Germany.